EOL Seminar: Bart Geerts (University of Wyoming)

Tuesday, December 2, 2014 - 03:30 to 04:30
FL2-1022 (Large Auditorium)
Contact Name: 
Steve Oncley
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Plains elevated convection at night: the PECAN project

Bart Geerts
University of Wyoming

The PECAN campaign (June-July 2015) is a multi-agency project (NSF, NOAA, NASA, DOE) designed to advance the understanding of continental, nocturnal, warm-season precipitation. PECAN will focus on nocturnal convection in conditions over the central Great Plains with a stable boundary layer (SBL), a low-level jet (LLJ) and the largest CAPE located above the SBL. Thunderstorms are most common after sunset across this region in summer, and much of the resulting precipitation falls from MCSs. To date, an accurate prediction and an in-depth understanding of elevated convection in this environment remains an elusive goal. While the initiation of deep convection (CI) in well-mixed daytime boundary layers occurs along pre-existing boundaries of surface convergence, the initiation of nocturnal convection above the SBL is poorly understood and relatively unexplored. Nocturnal CI and MCS maintenance may be controlled by vertical parcel displacements due to undular bores and non-linea r wave-like features triggered by the MCS cold pools. It remains uncertain how the dynamics and microphysics of MCSs evolve as the boundary layer stabilizes in response to nocturnal radiative cooling, and what controls the decoupling of strong winds from the surface. Finally, PECAN aims to improve NWP, in particular nocturnal QPF in the Great Plains, mainly by means of a mesoscale network of thermodynamic and kinematic profiling systems.

Tuesday, 2 December 2014, 3:30PM
NCAR-Foothills Laboratory
3450 Mitchell Lane
Bldg. 2 Large Auditorium (Rm 1022)
Webcast Link: http://www.fin.ucar.edu/it/mms/fl-live.htm